Hong Kong—The International Gemological Institute (IGI) Hong Kong is now the third IGI location to offer tanzanite grading in accordance with the Tanzanite Quality Scale, the only specific international grading system for tanzanite.

Beginning in North America in March 2007, the IGI became the first laboratory to adopt the Tanzanite Foundation's quality scale for tanzanite. The program was then rolled out to the IGI's locations in India.

"A key consideration for the Tanzanite Foundation in working with IGI to launch the tanzanite-grading initiative was IGI's global reach and reputation," Tanzanite Foundation Technical Director Gabriella Endin said in a statement. "IGI not only shares our vision for a universal, consistent tanzanite-grading system, but has the international presence, expertise and market positioning to play a key role in achieving this goal."

The trademarked Tanzanite Quality Scale grades stones according to the Four C's: carat weight, color, clarity and cut. A fifth "C" stands for confidence, the lab says. The IGI says its certificates provide the assurance that the tanzanite inspected is authentic and of natural origin—from the foothills of Mount Kilamanjaro in Tanzania, Africa—the world's only known tanzanite source.

In celebration of the Hong Kong launch, the Tanzanite Foundation and the IGI will host a presentation and cocktail event on Sept. 27 at the Hong Kong Convention and Exhibition Center.